( rlix ) 



been able to examine a sufficient series, I am unable to express 

 an opinion on tbem, but they are so peculiar and interesting 

 that it seems worth while to give at least one figure of the 

 group, though all are not enclosed in an outer case such as this. 

 The Asilidae, with varied and frequently complex organs, 

 are a deeply interesting family from other points of view as 

 well as the one I am considering; their mating habits should 

 be specially observed. I must, however, confine myself to 

 one genus. 



Dioctria rufipes 



has a fair-sized semi-tubular tegumen elongated into blunt 

 points at the lower apices, with a somewhat tusk-shaped 

 apophysis overlapping on each side ; the harpagones (or their 

 equivalent) are well developed, terminating in longish curved 

 processes; the aedoeagal ring is rather complex in its arma- 

 ture, the sedoeagus being a simple tapering irregular tube. 



The Empidae are of the utmost interest from the point of view 

 now under consideration, and some of us who are not Dipterists 

 are looking forward to Mr. Collin's classification of this im- 

 portant group from the anatomical standpoint. He tells 

 me that the habit of the male is to soar up from below and 

 seize the female from underneath. In accordance with this 

 habit the clasping armature is developed to meet it, this 

 being particularly the case with the sedoeagus, which is 

 upturned instead of occupying the usual position. 



Empis tessellata 



shows this excellently, the sedoeagus being highly curved 

 with an asymmetrical deeply bifid extremity; the tegumen 

 is quite small and bifid with a pair of small cuneate apophyses, 

 whilst a pair of very large lateral plates (reminding one of the 

 valves of the Papilionidae and of some of the Pieridae) cover 

 each side. I will not refer to more genera as Mr. Collin will 

 shortly, I hope, deal with the whole subject of this group. 



Of the Dolichopodidae I will only figure the one species 

 Dolichopus ungulatus. 



The tegumen has an extraordinarily developed uncal 

 apophysis with rather complex armature below its median 



